Question on oval/eliptical S&W rifling

[bobt]

Does any pro's out there know about a different than standard rifling that Smith used on a 5906, the bore sort of looks elongated or eliptical/oval,,,,,,,I heard something to the effect it boosted the muzzle velocity.

If this is true what is the correct term for this type rifling?

THX!

 

[bobt]

Does any pro's out there know about a different than standard rifling that Smith used on a 5906, the bore sort of looks elongated or eliptical/oval,,,,,,,I heard something to the effect it boosted the muzzle velocity.

If this is true what is the correct term for this type rifling?

THX!

 

[bobt]

ttt

 

[BillCa]

If looking down the bore of your 5906 (ideally empty of course!) and you don't see lands & grooves but something that looks like a squished sprialing square, it's likely you have a replacement barrel with polygonal rifling.

I don't know of S&W ever using this type of rifling on a factory barrel (unless it was some kind of Performance Center or Briley barrel).

 

[bobt]

Hey Billca, you are 1 of the few if any who knows about what I was talking about,,,,,,Thanks a MILLION!

I did a "search" on ploygonal and found a bunch of neat stuff about it.

These were on brand new 5906's, supposed to be the last run of them, I bought 2 of them and they both came with these barrels, maybe Smith getting rid of excess stock????

Thanks again!

 

[gmchenry]

I'm glad you got some help with this. I was lost at the bore being "eliptical/oval".

Polygonal rifling has been around for a while. The PC even has some revolvers with polygonal rifling. Glocks use polygonal rifling as do many SIGs.

 

[john traveler]

The Germans/Austrians developed the machines that hammer-forge the polygonal (eliptical) rifling that you speak of. The products of HK and Glock, for instance, are use eliptical type rifling as their trademarks.

Polygonal rifling claims to produce lower chamber pressures, high velocities, and are easier to clean as well as longer lasting. You decide if these are valid claims or just advertising hype. Snce the development of hammer forging, however, barrels are more economically mass produced, and to higher production accuracy standards compared to the old single hook cutters and the broached methods used throughout WWII and the Korean war.

Many US gun manufacturers used hammer forged barrels, although admittedly not in the polygonal rifling type.

Since the S&W acquisition of Walther (German), maybe they are making inroads into that type of rifling?